Welcome to the sickness
Good advice on the thread.
Swan Island is the safest and best place to learn. When the river is high and ripping, like it is now, it is about the only place that you can kayak fish.
I went to Swan Island yesterday and met up with a fellow from another site. I had the most prolific day of sturgeon fishing in my life. I caught 43 sturgeon before I ran out of bait. I think he caught 20-some. He also had big fish on the day with one that had to be close to 7'. The best part is that we were fishing less than 1000' from the launch. You could have easily used your hands to paddle out to where we were fishing. Right now the sturgeon are about as far back in the harbor as can be. You will never get an easier and safer chance to catch a sturgeon from your kayak.
Sturgeon do show on FFs, but they do not show up as well as some other fish. They make a smaller mark per size of fish. Right now they are so thick that often it is hard to see them, just that the bottom looks thicker. I actually can see them much better on the Down Imaging screen when they are thick like this. The higher frequency signal has better target separation. However, even if you did not have depthfinder it would not have mattered yesterday. There were multiple fish in the air constantly for the entire day. I have never seen so many fish jumping. It was crazy. At one point a sturgeon smashed into the bottom of my kayak as I rejected its jump attempt. Just crazy.
Jumpers are not always biters, but yesterday they definitely were. They were biting so well that I never anchored. I just used the paddle to hold me in place and watched the rod tip closely with the reel in free spool and the clicker on. Hardest part was that as soon as the bait hit bottom (and often on the way down) sturgeon would be running into your line. Great opportunity to get a lot of practice in feeling the difference between a sturgeon rubbing against your line and a sturgeon actually taking your bait.
If you can make it out there while the water is high and warm you will not be sorry. One thing is to make sure that you dress for immersion. The water is 50 degrees, which is warm for this time of the year, but that is still cold enough to kill warm blooded creatures like us via hypothermia. I own a drysuit, but I usually wear waders and a drytop and always a PFD. Never take that off while you are out in the yak.
Best of luck. I hope to see you out there one of these days.